The Clinical Materials Core provides other cores and project investigators with human cells and tissues from cystic fibrosis (CF) and non-CF volunteers for use in testing of compounds for CF therapy and in investigations of CF pathophysiology. Resources provided by the core include human cells and tissues, physiological measures of CFTR function and clinical data. The materials made available by Core B to other cores and project investigators include: nasal epithelial cells, nasal polyps, nasal biopsy fragments, segments of trachea, main stem and intraparenchymal bronchi, rectal biopsy fragments, blood and expectorated or induced sputum. Materials are collected from CF and non-CF volunteers who range in age from early childhood up. Many of these materials, such as nasal epithelial cells from nasal brushings and polyps, are provided to Core C (Cell Models) for processing and culture on permeable membranes or as spheroids. Some airway fragments are provided directly to Core E (Cell and Tissue Bioassays) or after processing by Core C. In other cases fresh tissue fragments go directly to investigators for specific translational projects, such as studies of submucosal gland secretions in fragments of nasal epithelium and of airway surface liquid (ASL) in tracheal segments. The supply of cells and tissues is critical to the missions of the majority of Center projects, and to date Core B has supplied nearly 500 specimens of human cells, tissues and sputum to other cores and investigators. We anticipate an increased number of samples to be collected in the next 5 years for use in compound discovery and testing, and in translational research.